769. Comparison of Vancomycin Continuous and Intermittent Infusion Dosing Strategies Among Patients in an Outpatient Antimicrobial Therapy Program

Abstract

BackgroundVancomycin may be administered via intermittent infusion (I-I) or continuous infusion (C-I). C-I vancomycin has advantages including the potential for less nephrotoxicity; however, available data are inconsistent and varies based on inpatient and outpatient settings. Thus, the primary objective of this study was to compare rates of nephrotoxicity in patients who received C-I or I-I vancomycin in an outpatient parenteral antimicrobial therapy (OPAT) program. Secondary objectives included time to onset of nephrotoxicity and clinical failure.MethodsThis was a single-center, propensity score-matched, retrospective cohort study of patients who received C-I or I-I vancomycin for at least one week in the OPAT program between October 1, 2017 and March 31, 2019. Exclusion criteria included patients lost to follow-up, age less than 18 years old, and those requiring renal replacement therapy. Nephrotoxicity was defined as a serum creatinine (Scr) increase of >0.5 mg/dL or >50% from baseline for two consecutive measurements. Clinical failure was defined as unplanned readmission, extension of planned therapy, or change in antibiotic therapy.ResultsThree hundred patients were identified who received C-I or I-I vancomycin. After propensity score matching and exclusion criteria were applied, 74 patients were included in each cohort. Demographic information was similar between cohorts including baseline Scr, age, gender, comorbidities, concurrent nephrotoxins, indication, and vancomycin duration. C-I was associated with a 3.22-fold decrease in nephrotoxicity risk when compared with I-I [C-I: 6.8% vs. I-I 18.9%; OR (95% CI): 3.22 (1.10–9.46), P =0.027]. C-I was associated with a significantly slower onset to nephrotoxicity compared with I-I (P = 0.035; Figure 1). A significant difference in clinical failure was not observed between C-I and I-I (10/74, 13.7% vs. 17/74, 23.0%; P = 0.147).ConclusionC-I vancomycin was associated with a lower nephrotoxicity risk and slower onset to nephrotoxicity, but no difference in clinical failure rates when compared with I-I. Disclosures All authors: No reported disclosures.